Gel formation of soybean 7S and 11S proteins.

Abstract

Rheological properties of soybean 7S and 11S proteins were investigated at the concentrations in which both could form the heat-induced gel. It was recognized that 7S protein formed gel at the lower concentration than that of 11S protein. In forming gel, 11S protein seems to have the ability to form more hydrogen bonds and ionic attractions and less hydrophobic interactions than those of 7S protein. In the presence of salts, the gel of 7S protein was formed at the lower protein concentration compared with the absence of salts. But the addition of salts to 11S protein suppressed the formation of gel even with high protein concentration. The reactivity of carboxyl groups was determined by the dye-binding method. The 11S protein contained reactive carboxyl groups.